Question about jointAccelerations initialization in WbcBase.cpp

[Libre007]

Hello, I was reading the paper "A Unified MPC Framework for Whole-Body Dynamic Locomotion and Manipulation" and noticed that in the WbcBase.cpp file, on line 135, the jointAccelerations are set to zero:

const vector_t jointAccelerations = vector_t::Zero(info_.actuatedDofNum);

However, the paper suggests that joint accelerations should be obtained through finite differences rather than being initialized to zero. Could you please clarify why this initialization is necessary and how it aligns with the methodology described in the paper?